CLEANUP: Context.{Rel,Named}.Declaration.t

  Originally, rel-context was represented as:

    Context.rel_context = Names.Name.t * Constr.t option * Constr.t

  Now it is represented as:

    Context.Rel.t = LocalAssum of Names.Name.t * Constr.t
                  | LocalDef of Names.Name.t * Constr.t * Constr.t

  Originally, named-context was represented as:

    Context.named_context = Names.Id.t * Constr.t option * Constr.t

  Now it is represented as:

    Context.Named.t = LocalAssum of Names.Id.t * Constr.t
                    | LocalDef of Names.Id.t * Constr.t * Constr.t

Motivation:

  (1) In "tactics/hipattern.ml4" file we define "test_strict_disjunction"
      function which looked like this:

        let test_strict_disjunction n lc =
          Array.for_all_i (fun i c ->
            match (prod_assum (snd (decompose_prod_n_assum n c))) with
            | [_,None,c] -> isRel c && Int.equal (destRel c) (n - i)
            | _ -> false) 0 lc

      Suppose that you do not know about rel-context and named-context.
      (that is the case of people who just started to read the source code)
      Merlin would tell you that the type of the value you are destructing
      by "match" is:

        'a * 'b option * Constr.t                    (* worst-case scenario *)

      or

        Named.Name.t * Constr.t option * Constr.t    (* best-case scenario (?) *)

      To me, this is akin to wearing an opaque veil.
      It is hard to figure out the meaning of the values you are looking at.
      In particular, it is hard to discover the connection between the value
      we are destructing above and the datatypes and functions defined
      in the "kernel/context.ml" file.

      In this case, the connection is there, but it is not visible
      (between the function above and the "Context" module).

      ------------------------------------------------------------------------

      Now consider, what happens when the reader see the same function
      presented in the following form:

        let test_strict_disjunction n lc =
          Array.for_all_i (fun i c ->
            match (prod_assum (snd (decompose_prod_n_assum n c))) with
            | [LocalAssum (_,c)] -> isRel c && Int.equal (destRel c) (n - i)
            | _ -> false) 0 lc

      If the reader haven't seen "LocalAssum" before, (s)he can use Merlin
      to jump to the corresponding definition and learn more.

      In this case, the connection is there, and it is directly visible
      (between the function above and the "Context" module).

  (2) Also, if we already have the concepts such as:
      - local declaration
      - local assumption
      - local definition
      and we describe these notions meticulously in the Reference Manual,
      then it is a real pity not to reinforce the connection
      of the actual code with the abstract description we published.

1 files changed, 5 insertions, 3 deletions

diff --git a/plugins/funind/indfun.ml b/plugins/funind/indfun.ml
index d1e1098259..86abf9e2ef 100644
--- a/plugins/funind/indfun.ml
+++ b/plugins/funind/indfun.ml
@@ -1,3 +1,4 @@
+open Context.Rel.Declaration
 open Errors
 open Util
 open Names
@@ -13,10 +14,10 @@ open Decl_kinds
 open Sigma.Notations
 
 let is_rec_info scheme_info =
-  let test_branche min acc (_,_,br) =
+  let test_branche min acc decl =
     acc || (
       let new_branche =
-	it_mkProd_or_LetIn mkProp (fst (decompose_prod_assum br)) in
+	it_mkProd_or_LetIn mkProp (fst (decompose_prod_assum (get_type decl))) in
       let free_rels_in_br = Termops.free_rels new_branche in
       let max = min + scheme_info.Tactics.npredicates in
       Int.Set.exists (fun i -> i >= min && i< max) free_rels_in_br
@@ -153,7 +154,8 @@ let build_newrecursive
 	let evdref = ref (Evd.from_env env0) in
 	let _, (_, impls') = Constrintern.interp_context_evars env evdref bl in
 	let impl = Constrintern.compute_internalization_data env0 Constrintern.Recursive arity impls' in
-        (Environ.push_named (recname,None,arity) env, Id.Map.add recname impl impls))
+        let open Context.Named.Declaration in
+        (Environ.push_named (LocalAssum (recname,arity)) env, Id.Map.add recname impl impls))
       (env0,Constrintern.empty_internalization_env) lnameargsardef in
   let recdef =
     (* Declare local notations *)